Factors Protecting Male and Female Adolescents in Mexico From Human Papillomavirus Infection

Adolescent Development and Sexual Behavior: Focusing on Protective Behavior

HPV infection, particularly the oncogenic type, poses significant health risk during adolescence due to its high transmission rate during the first sexual encounter (Castellsagué et al., 2014). Exposure to HPV can occur via anal, oral, or vaginal sexual relations (Gonzalez-Losa et al., 2016). An example of high-risk exposure to HPV occurs when adolescents have first sexual relationships with sexually experienced partner, even though currently in monogamous sexual relationships (Winer et al., 2008; Zou et al., 2014).

Number of sexual partners (Ribeiro et al., 2014) and inconsistent condom use (Shew et al., 2006) are considered risk factors for HPV. Adolescents reportedly do not use or improperly use condoms during their first sexual intercourse (Ayhan et al., 2015). Rivera-Rivera et al. (2016) found that average age of first intercourse in Mexico was 16 years. Adolescents living in Mexico also report limited condom use at first intercourse (33.4% females, 14.7% males; Instituto Nacional de Salud Pública, 2012). These findings highlight vulnerability to contracting HPV among adolescents living in Mexico.

The HPV vaccine protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 (McLemore, 2006). Health policy in Mexico mandates administration of the vaccine only among females aged 10 to 11 years who are not sexually active. Those who have been sexually active are not eligible for administration of the vaccine because they may have already acquired an HPV infection.

Infection with a specific HPV type does not preclude the need for protection from other HPV types (National Cancer Institute, 2016). Therefore, recommendation for condom use in addition to HPV vaccination provides greater protection against HPV types not covered by the vaccine (Miksis, 2008). Vaccination for men in countries with scarce resources is not prioritized (Organizacion Mundial de la Salud, 2014). Hence, HPV prevention strategies among men in Mexico focus primarily on condom use, which, if used consistently and effectively, can provide good protection and reduce the risk of HPV infection (Lam et al., 2014; Nielson et al., 2010). Prevention strategies also include limitation of number of sexual partners and monogamous relationships (Giuliano et al., 2011).

Gender stereotypes related to sexuality exist in Mexico and affect HPV prevention measures. These gender stereotypes indicate that men need more sexual relationships than women (Cubillas et al., 2016) and must initiate sexual relationships and condom use (Hernández & González, 2016).These gender stereotypes influence sexual behavior and promote sexual risk behaviors, including limited condom use negotiation (Bárcena, Rendón, & Robles, 2011), thereby affecting sexual rights (United Nations Human Rights, 2014). Little is known about effect of sexual rights knowledge on sexual behavior. Rohrbach et al. (2015) found that rights-based sexuality education has positive effects on adolescent sexual behavior. These findings indicate knowledge concerning sexual rights has positive effects on sexual behavior among adolescents in Mexico.

HPV prevention studies indicate that different factors have effects on implementation of HPV prevention programs and outcomes. Mullins et al. (2012) found that American adolescents perceived less need for safe sexual behaviors after HPV vaccination. Personal factors and HPV risk behaviors can have positive effects on attitudes toward HPV prevention, cervical cancer, and intention to acquire the HPV vaccine (Kang & Moneyham, 2010; Marek, Berenyi, Dergez, Kis, & D’Cruz, 2016). Other factors include perception of self-efficacy, which influences commitment to obtain HPV vaccination (Ping-Fen, Ying-Tse, Shuh-Jen, & Tze-Fang, 2014).

Several studies explored condom use as a HPV prevention measure. These studies found an association between perceived behavioral control and intention to use condoms for HPV prevention (Kang, & Moneyham, 2010; Tu, Wang, Lin, & Chan, 2015). Brüll, Ruiter, Wiers, and Kok (2016) found subjective norms (peer pressure) predicted intentions to use condoms among German adolescents.

Other factors such as reading HPV information have been associated with intent to obtain the HPV vaccine and use condoms for HPV prevention (Stock, Peterson, Houlihan, & Walsh, 2013). Evidence is limited concerning factors predicting HPV prevention behaviors among adolescents in Mexico. Vogtmann, Harlow, Valdez, Valdez, and Ponce (2011) have reported that limited knowledge about HPV and its prevention strategies exists among Mexican adolescents.

The health promotion model was adapted to examine factors influencing HPV prevention among adolescents in Mexico within three broad categories: (1) individual characteristics and previous behavior (age, gender, HPV knowledge, sexual rights, number of sexual partners, condom use, and age of first sexual experience), (2) specific behavioral cognitions and affections (perceptions of self-efficacy and social influences), and (3) the behavioral outcome of interest (health protective behavior or safe sexual practice; Pender, Murdaugh, & Parsons, 2015).

Purpose

Our study examines factors associated with HPV protective behavior among adolescents living in Mexico aged 15 to 17 years. Factors examined to describe safe sexual practice include age, gender, past sexual behavior, HPV knowledge, knowledge about sexual rights, perceptions of condom use self-efficacy, interpersonal influences on HPV protective behavior, and having a condom use action plan.

Sample

A descriptive correlational, cross-sectional design was used to examine factors related to HPV protective behavior among adolescents living in Mexico. Male and female adolescents aged 15 to 17 years of age were recruited via convenience sampling from three public high schools. Adolescents were excluded if they were already married, living with partners or had children.

Procedure

This study was approved by the ethics and research board. Permission for the administration of this study was obtained from appropriate administrative authorities of public high schools in which the questionnaires were applied. Administrative authorities of the public schools provided consent for adolescent participation in the study followed by adolescent assent. This procedure met the guidelines recommended by the Reglamento de la Ley General de Salud en Materia de Investigación para la Salud (Regulations of the General Health Law regarding Health Research Affairs). According to Article 36, “In order to carry out investigations of minors…, the written consent document must be obtained from those who exercise parental authority or the legal representation of the minor.” Administrative authorities were considered legal representative of the adolescents as the study was conducted in the school setting. Additionally, according to Article 38, “Investigations classified as risk and with probability of direct benefit for the minor…will be admissible when: I. The risk is justified by the importance of the benefit that the child will receive.” Article 38 was applicable in this study as the assessments were conducted to describe characteristics of the adolescents for development and implementation of a HPV prevention intervention at the school (Secretaría de Salud, 1987).

Administrative authorities identified three to four groups in each high school and corresponding times and dates for conduct of the study not interfering with classroom teaching. Potential participants were approached in the classroom by the principal investigator and invited to participate in the study. Potential participants received explanations of study purpose and participant role. They were also made aware that participation was voluntary. The potential participants read the assent form and, if agreeing to participate, subsequently completed informed consent. Following completion of this process, questionnaires were administered to the participants in the classroom setting. Adolescents received instructions about how to respond to each questionnaire. The principal investigator and research assistant were available to answer questions during questionnaire completion.

Instrumentation

Measurements included self-administered questionnaires. Items were included to assess sociodemographic data such as age and gender. Questionnaire items also related to sexual behavior (age at first sexual intercourse, type of sexual relationship, number of partners in lifetime, and past 3 months, condom use in most recent relationship and in the past 3 months, and partner relationship). The participants were asked whether they had heard about HPV. Female participants were asked if they had received HPV vaccination.

Prior to utilization for this study, instruments were initially translated from English to Spanish by two bilingual professionals. A review of the translation by an expert investigator was conducted to ensure that content and translation were appropriate for Mexican adolescents. Reliability coefficients were obtained for all scales and are reported in this study.

HPV knowledge was measured using a subscale of the HPV-General Knowledge and HPV-Vaccine Knowledge Scale (Pérez et al., 2016). The original scale consisted of two subscales constituting a total of 36 items: 25 items correspond to general knowledge about HPV and 11 correspond to HPV vaccination. For purposes of this study, only the HPV knowledge subscale was selected. This subscale encompasses a format of affirmative sentences to which participants have the option to select among three responses: yes, no, and I don't know. Two items, originally not a part of the subscale, were added using the same format. These items included (1) there is a vaccine to prevent HPV infections and (2) changes in the result of the pap smear could indicate that a woman has HPV. HPV-knowledge scores were calculated by assigning 1 point to each correct answer and zero points for incorrect or “don’t know” answers (range 0-27). Cronbach alpha coefficient of the scale was α = .72.

Sexual rights knowledge was assessed via the Sexual Rights Awareness Scale (Kim, Im, & Kim, 2010). This scale consists of 17 items measuring five domains of an individual's sexual rights, including sexuality education, prejudice and bias aberration, sexual satisfaction, safe and equal sexuality, and sexual autonomy. The scale includes Likert responses ranging from 1 = totally disagree to 4 = totally agree, with higher scores indicating better knowledge. The scale reliability was acceptable overall (α = .822).

Self-efficacy for condom use was measured using the Condom Use Self-Efficacy Scale (Brafford & Beck, 1991). This scale consists of 28 items describing an individual’s feelings of confidence about being able to purchase condoms, put them on and take them off, and negotiate their use with a new sexual partner. Each item has a 5-point strongly disagree (scored as 0) to strongly agree (scored as 4) response format. After reversing for negatively worded items, the scores are summed to yield the total score ranging from 0 to 112, with higher scores indicating greater condom self-efficacy. The scale had good reliability (α = .918).

Interpersonal influence for HPV protective behavior was measured via the Subjective Norm Survey (Sweeney, McAnulty, Reeve, & Cann, 2015). This survey includes 10 questions assessing social pressure to conduct behaviors that decrease the risk of becoming infected with HPV (i.e., using a condom with one’s partner, decreasing the number of sexual partners). The Likert-type responses range from 0 = strongly disagree to 4 = strongly agree, with higher scores indicating greater social pressure. Scale reliability for this study was acceptable (α = .864).

The action plan for condom use was measured using Strength of Implementation Intentions Scale for Condom Use (Nydegger, 2015). This scale includes nine items indicating whether or not the individual has plans about how and when to take, purchase, and use a condom. Three questions were added for this study addressing when, how, and where to buy condoms. This Likert scale has responses ranging from 1 = strongly disagree to 6 = strongly agree. The higher score indicates greater strength in intention to implement condom use. The Cronbach’s alpha for the scale was high (α = .90).

HPV protective behavior was measured by the Safe Sex Behavior Questionnaire only among participants who reported past sexual experience. This scale contains 24 questions measuring frequency of safer behaviors in four areas: protection during intercourse, avoidance of risk behaviors, avoidance of bodily fluids, and interpersonal skills. The 4-point Likert scale responses range from 1 = never to 4 = always, with total scale scores ranging from 24 to 96 and higher scores indicting greater frequency of safer sex behavior. Scale reliability for this study was acceptable (α = .806).

Data Analysis

Data were analyzed using Statistical Package for the Social Sciences Version 20 (IBM Corp, 2011). Descriptive statistics included frequencies and percentages for categorical variables and measures of central tendency and dispersion for ordinal variables.

Variables constituting continuous values for this study were normally distributed. Inferential analysis was conducted as follows. The sample was initially categorized by sexual experience and by gender. Next, t tests or chi-square analyses as appropriate were conducted to provide group comparisons. Logistic regression was then conducted to determine whether factors (gender, knowledge of sexual rights, condom self-efficacy, and plan for condom use) predicted sexual experience among all adolescents. Specifically, among adolescents reporting previous sexual experience, bivariate Pearson product correlations were used to explore associations between HPV protective behavior and associated factors. Multiple linear regression analysis was then performed to identify variables predicting HPV protective behavior.